title: Iodine deficiency in 2007: global progress since 2003.
abstract: BACKGROUND
  Iodine deficiency is a global public health problem, and estimates of the extent of the problem were last produced in 2003.
  
  
  OBJECTIVE
  To provide updated global estimates of the magnitude of iodine deficiency in 2007, to assess progress since 2003, and to provide information on gaps in the data available.
  
  
  METHODS
  Recently published, nationally representative data on urinary iodine (UI) in school-age children collected between 1997 and 2006 were used to update country estimates of iodine nutrition. These estimates, alongside the 2003 estimates for the remaining countries without new data, were used to generate updated global and regional estimates of iodine nutrition. The median UI was used to classify countries according to the public health significance of their iodine nutrition status. Progress was measured by comparing current prevalence figures with those from 2003. The data available for pregnant women by year of survey were also assessed.
  
  
  RESULTS
  New UI data in school-age children were available for 41 countries, representing 45.4% of the world's school-age children. These data, along with previous country estimates for 89 countries, are the basis for the estimates and represent 91.1% of this population group. An estimated 31.5% of school-age children (266 million) have insufficient iodine intake. In the general population, 2 billion people have insufficient iodine intake. The number of countries where iodine deficiency is a public health problem is 47. Progress has been made: 12 countries have progressed to optimal iodine status, and the percentage ofschool-age children at risk of iodine deficiency has decreased by 5%. However, iodine intake is more than adequate, or even excessive, in 34 countries: an increase from 27 in 2003. There are insufficient data to estimate the global prevalence of iodine deficiency in pregnant women.
  
  
  CONCLUSIONS
  Global progress in controlling iodine deficiency has been made since 2003, but efforts need to be accelerated in order to eliminate this debilitating health issue that affects almost one in three individuals globally. Surveillance systems need to be strengthened to monitor both low and excessive intakes of iodine.
authors.affiliation: Department of Nutrition for Health and Development, World Health Organization, CH 1211 Geneva 27, Switzerland.
authors.forename: Bruno
authors.initials: B
authors.lastname: de Benoist
authors.forename: Erin
authors.initials: E
authors.lastname: McLean
authors.forename: Maria
authors.initials: M
authors.lastname: Andersson
authors.forename: Lisa
authors.initials: L
authors.lastname: Rogers
mesh_terms: D000328:Adult; D002648:Child; D003625:Data Collection; D005260:Female; D005527:Food, Fortified; D014943:Global Health; D006306:Health Surveys; D006801:Humans; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency* / Q000652:urine; D008297:Male; D044342:Malnutrition / Q000188:drug therapy; D009752:Nutritional Status; D011247:Pregnancy; D016730:Program Development; D017673:Sodium Chloride, Dietary; D013959:Thyroid Diseases / Q000188:drug therapy
chemical_list: D017673:Sodium Chloride, Dietary; D007455:Iodine